//
// Created by shuhongfan on 2020/10/27.
//

#include <stdio.h>

int main(){
    char ch1[]="hello";
    char ch2[]="world";
    char ch3[20];

    int i=0;
    int j=0;
    while (ch1[i]!='\0'){
        ch3[i]=ch1[i];
        i++;
    }
    while (ch2[j]!='\0'){
        ch3[i+j]=ch2[j];
        j++;
    }
    ch3[i+j]="\0";
    printf("%s",ch3);
}